I have a custom board using the LM5088MHX-2/NOPB to generate a -20V @ 1A and a second to generate -15V @1A. These are also used in conjunction with some positive output supplies that share a ground.
I have a lot of noise, and have turned off all supplies except the -15V supply to isolate the noise. On the output of the -15V supply there are spikes near the switching frequency of several volts in magnitude. I used values straight out of webbence, however can't seem to get webbench to give me a schematic again with this part. Any ideas what might cause this? The noise is large enough that it seems something is connected very wrong. I've attached a snapshot of the schematic. The input is +24V from a battery.